The MySQL server listens on one or more network sockets for TCP/IP connections. Each socket is bound to one address, but it is possible for an address to map onto multiple network interfaces.
variable at server startup to specify the TCP/IP connections
that a server instance accepts. As of MySQL 8.0.13, you can
specify multiple values for this option, including any
combination of IPv6 addresses, IPv4 addresses, and host names
that resolve to IPv6 or IPv4 addresses. Alternatively, you can
specify one of the wildcard address formats that permit
listening on multiple network interfaces. A value of *, which is
the default, or a value of
::, permit both
IPv4 and IPv6 connections on all server host IPv4 and IPv6
interfaces. For more information, see the
bind_address description in
Section 5.1.8, “Server System Variables”.